Prostate cancer is a leading healthcare concern in North America and Europe. There were an estimated 232,090 new cases of prostate cancer diagnosed in 2005 in the United States, and over 30,350 deaths from advanced metastatic disease. Prostate cancer is now the most commonly diagnosed lethal malignancy, and the second leading cause of cancer death of men in the United States. Although curative treatment (e.g., radical prostatectomy or radiotherapy) is feasible for many patients with the earliest stage disease, early diagnosis remains a challenge. If prostate cancer becomes metastatic, the median survival for such patients is approximately one year. There remains an urgent need for determining those at risk for or susceptible to prostate cancer, early-stage prostate cancer prognosis, and early intervention.
Prostate specific antigen (PSA) screening has led to earlier detection of PCA and significantly reduced PCA-associated fatalities. However, a major limitation of the serum PSA test is a lack of prostate cancer sensitivity and specificity especially in the intermediate range of PSA detection (4-10 ng/ml). Elevated serum PSA levels are often detected in patients with non-malignant conditions such as benign prostatic hyperplasia (BPH) and prostatitis, and provide little information about the aggressiveness of the cancer detected. Coincident with increased serum PSA testing, there has been a dramatic increase in the number of prostate needle biopsies performed. This has resulted in a surge of equivocal prostate needle biopsies. Thus, development of additional serum and tissue biomarkers or additional methods to detect a patient at risk for prostate cancer are urgently required.